With function enhancement, the volume of data in systems such as digital TV sets and recorders has been dramatically increased. As a result, an increase in memory capacity and a high data transmission rate have been required for semiconductor memories mounted on the systems.
Examples of semiconductor devices including the foregoing semiconductor memories include system-on-chips (SoCs), each of which is a single chip into which a semiconductor logic circuit chip on which a memory controller is mounted and a memory are integrated. Moreover, the examples also include system-in-packages (SiPs) in each of which a semiconductor logic circuit chip on which a memory controller is mounted and a memory chip are stacked on each other and are housed in a single package.
Recently, systems using SiPs manufactured at relatively low cost have been increased.
For such semiconductor devices, a method using a chip-on-chip (CoC) technique is employed as a method for electrically connecting the semiconductor logic circuit chip and the memory chip together. According to such a method, the semiconductor logic circuit chip and the memory chip are, at electrodes thereof, directly connected together through metal protrusions made of, e.g., solder, gold, or copper such that a circuit formation surface of the semiconductor logic circuit chip and a circuit formation surface of the memory chip face each other. This method has been broadly used for the purpose of increasing a data transmission rate.
A semiconductor device described in Japanese Unexamined Patent Publication No. 2010-141080 (hereinafter referred to as “Patent Document 1”) is an example of the configuration in which an access from external terminals of a package to functions of a semiconductor logic circuit chip is made. That is, electrodes are formed within an outer circumferential region of the logic circuit chip which does not face a memory chip, and, e.g., wire bonding is used to connect the electrodes respectively to electrodes formed on an adjacent substrate through thin metal wires made of, e.g., gold, aluminum, or copper.